Acoustic-electric guitar preamp with advanced BOSS sound processing Sophisticated under-the-hood processing with multiple interlocked parameters, accessible with simple stompbox controls Acoustic Resonance reproduces the complex resonance characteristics of an unplugged acoustic Ambience knob provides wide-ranging, studio-quality reverb optimized for acoustic guitar Notch filter for instant feedback reduction Normal output for an acoustic guitar amp and balanced DI output for direct PA connection Sound mute function for switching guitars and tuning on stage